Simeon s



3. s. & A. J. POST.

Refiector.

Patented July 16, 1861.

nivrrnn STATES rarnnr ermos.

SIMEON S. POST AND ANDREW J. POST, OF JERSEY CITY, NIE-'W JERSEC, ASSIGNORS TO A. J.

POST AND EDXVD. O. CLARK, Oli' PIEDMONT, NIMV YORK.

LAMP.

Specificaton of Letters Patent No. 32,851, dated July 16 1861. i

To al whom 'it may concem:

Be it known t-hat we, SIMEON S. Posr and ANDREW J. Pos'r, of Jersey City, in the County of Hudson, in the State of New Jersey, have invented a certain new and useful Improvement in Refiectors for Lamps Intended More Especially for I-Ieadlights for liocomotives; and we do hereby declare that the following is a full and exact description of the same, reference being had t-o the accompanying drawings, in which- Figure l is a vertical section on the aXial line G, G. F ig. 2 is a dagram giving a comparative view of the eflect of this and the ordinary refiector.

similar letters of reference indicate like parts in both drawings.

A is a case or framing of the ordinary character.

B is a burnished refiector made of a paraboloidal form and mounted in the usual manner 011 supports b, b, inserted in hollow stands a, a. The paraboloid B is not complete but its smaller end is absent as represented.

A lamp O with a suitable chimney is mounted on a sliding carriage D so that it can be readily placed with its fiame in the focus and removed at pleasure. The slide D and its guides E are so located that the lamp is held in very close proXimity to the edges of B.

M is a separate reflector made in a paraboloidal form and fixed upon the lamp slide D very close to the lamp. It is mounted in such position that When the lamp is in its place the aXes of M and B coincide. The reflector M is more flattened or broad than B. By this we mean that the reflector M although actually smaller than B is cut from or may be conceived to form a part of a .larger paraboloid. vVe place M in such position on D that the foci of the two paraboloids and coincide in position both being exactly in the brightest portion of the fia1ne, designated by a star, The area of space covered by the rear reflector M is equal to or a little greater than that of the Opening in the rear of the front reflector B. Around the edgeof M is fiXed a band N of burnished metal of such breadth as to eXtend across the interval between it and the rear edge of B. This band is open or omitted at the points n, n,'directly above and below the Common focus of the refiectors.

is at right angles to the aXis as represented or may stand in other positions so that D shall move obliquely as it is withdrawn from B or they may be Curved so that on withdrawing D it shall first move backward nearly or exactly in the line of the aXis of the paraboloids and afterward When it has by a movement in that direction caused the lamp chimney and all the parts carried on the slide to be Well separated from the front refiector it shall then move laterally.

Itwill be observed that no portion of the light is twice refiected except that which strikes on the band N. This latter is in great part ultimately utilized by a duplication of the refiections on the surfaces but all other rays are thrown directly in the proper parallel lines, those from M being projected eXactly like those from the corresponding part of an ordinary paraboloidal mirror While those from B are also thrown in the same manner eXcept that the paraboloid is of a deeper or more acute form than those ordinarily employed.

Our invention utilizes much light which would otherwise be diffused. ln all reectors of this class the effect sought is to project the rays of light in a nearly parallel direction. All the direct or unrefiected rays which diverge more than about three degrees from the aXial line are lost. T11 the use of the ordinary single paraboloidal form of reflector all the light within the cone P, l? eXcept the slender pencil X, is diftused and lost by reason of the form of the reflector and this form cannot be changed to one more nearly akin to our refiector B because such change would bring the focal point too near the reflecting surface directly behind it. In our invention the form of B limits the quantity of rays thus diifused to the cone T, T, which is smaller than P, P, While the difliculty above pointed out as attending the use of such a form of refiector is obviated by our invention.

Beyond the mere use of the two refiectors arranged as described our invention involves the novel feature of advantage n the fact J employment of the part 01- f rus tum of a that the rear refiector M and the edge band N thereof are mounted on the lamp Slide D and carred therewth because it allows the space between B and M to be less and consequently the proporton of the rays subject to double and triple reflecton by strkng N to be less than any means before known for such pnl-pose.

HaVng now fully descrbed our nventon What We claim as new therein and desire to secure by Letters Patent, s-

In the Construction of lamp refiectors the smaller paraboloid mounted n front f the 15 paraboloid M and so arranged that their aXes and foc coincide so as to produce the eflect heren set forth.

In testmony whereof We have hereunto set our hands n the presence of two sub- 20 scrbng Wtnesses.

SIMEON S. POST. ANDREV J POST. 4 VVitnesses:

THOMAS D. STETSON, WM. B. SMITH. 

